rust/tests/ui/match/match-ref-mut-stability.rs
2024-02-16 20:02:50 +00:00

38 lines
877 B
Rust

// Check that `ref mut` variables don't change address between the match guard
// and the arm expression.
//@ run-pass
// Test that z always point to the same temporary.
fn referent_stability() {
let p;
match 0 {
ref mut z if { p = z as *const _; true } => assert_eq!(p, z as *const _),
_ => unreachable!(),
};
}
// Test that z is always effectively the same variable.
fn variable_stability() {
let p;
match 0 {
ref mut z if { p = &z as *const _; true } => assert_eq!(p, &z as *const _),
_ => unreachable!(),
};
}
// Test that a borrow of *z can cross from the guard to the arm.
fn persist_borrow() {
let r;
match 0 {
ref mut z if { r = z as &_; true } => assert_eq!(*r, 0),
_ => unreachable!(),
}
}
fn main() {
referent_stability();
variable_stability();
persist_borrow();
}